To address this limitation, this study evaluated microwave (MW) treatment as a rapid, uniform, and bioactivity-preserving alternative to HoP. Microwave heating was applied at 300 W for 1, 2, and 3 minutes, achieving final temperatures of 60.1 °C, 66.8 °C, and 72.1 °C, respectively. Microbial inactivation results demonstrated that a 2-minute MW treatment achieved greater than 5-log reductions in vegetative pathogens, including Cronobacter sakazakii (6.78 ± 0.54), Listeria monocytogenes (6.7 ± 0.17), Staphylococcus aureus (6.1 ± 0.94), and Enterococcus faecium (5.9 ± 0.73), in compliance with safety standards (Terpstra et al., 2007). Importantly, MW-treated milk preserved significantly higher levels of key bioactive components compared to HoP. Lactoferrin retention was consistently above 90% across all microwave durations, in contrast to ~35% in HoP-treated milk. BSSL activity, critical for fat digestion in neonates, retained approximately 40% activity following 2-minute MW treatment but remained below detection limits after HoP. Similarly, secretory IgA—an essential immunoglobulin for mucosal defense—was retained at levels exceeding 80% in MW-processed samples, compared to only 42% after HoP. Elastase, another bioactive enzyme with antibacterial function, was preserved at 58% post-MW, whereas HoP completely inactivated this enzyme. Interestingly, lysozyme, osteopontin, and vascular endothelial growth factor (VEGF) showed no significant differences between MW and HoP, suggesting their thermal stability under both processing methods.
To improve process predictability and bioactive retention, the study employed modeling of effective microwave penetration depth and effective treatment temperature, using the dielectric and thermal properties of DHM to optimize energy delivery and minimize surface overheating. These parameters were instrumental in achieving uniform heating and mitigating localized protein denaturation within this optically dense and colloidal matrix. These findings position microwave treatment as a clinically promising, scalable alternative to conventional HoP. The method combines microbial safety with enhanced preservation of functional milk components and is compatible with continuous-flow systems and aseptic packaging, enabling smooth integration into existing milk bank infrastructure. As the global need for high-quality donor milk continues to rise, this work offers a viable pathway to redefine pasteurization practices and improve infant health outcomes.
Future investigations will include broader proteomic profiling and functional validation in neonatal models to support regulatory approval and clinical translation. This research aligns with the overarching goal of developing next-generation donor milk processing technologies that preserve both safety and the biological integrity of human milk.
References:
Liang, N., Mohamed, H., Pung, R. F., Waite-Cusic, J., & Dallas, D. C. (2024). Optimized ultraviolet-C processing inactivates pathogenic and spoilage-associated bacteria while preserving bioactive proteins, vitamins, and lipids in human milk. Journal of Agricultural and Food Chemistry, 72(21), 12198-12208.
Peila, C., Moro, G. E., Bertino, E., Cavallarin, L., Giribaldi, M., Giuliani, F., ... & Coscia, A. (2016). The effect of holder pasteurization on nutrients and biologically-active components in donor human milk: a review. Nutrients, 8(8), 477.
Terpstra, F. G., Rechtman, D. J., Lee, M. L., Hoeij, K. V., Berg, H., Engelenberg, F. A. V., & Wout, A. B. V. T. (2007). Antimicrobial and antiviral effect of high-temperature short-time (HTST) pasteurization applied to human milk. Breastfeeding Medicine, 2(1), 27-33.